Brest Fortress, formerly known as Brest-Litovsk Fortress, is a 19th-century Russian fortress in Brest, Belarus, the former Byelorussian SSR. In 1965, the title Hero Fortress was given to the Fortress to commemorate the defence of the frontier stronghold during the first week of the German-Soviet War, when Nazi Germany turned on its former ally on June 22, 1941, with the launch of World War II's Operation Barbarossa.